Several times now during the last week or so watching UO twitch streams I see that everyone loves thievery. The people playing and the people watching, thievery is always a huge hit. Had MO2 launched with Thievery when there was like 6000 people trying to get into play it'd be way more popular today.
All those solo players would have had something to do, something fun, and would have stuck around long enough to probably later guild up with some like minded people to roll a non thief alt with and turned into long term players. MO2 really dropped the ball withholding thievery.